summaryrefslogblamecommitdiffstats
path: root/espFtpServer.cpp
blob: 96f7f3ec12123b71392499c621761481dc600ad8 (plain) (tree)
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769






















                                                                                       

















































































                                                                          























                                                        



                                               



























































































































































































































































































































































































































































































































































































































































                                                                                                                                          

                                                      
           

                                                             


              

                                                                    





































                                                                                            
                                   
           

                                                                                         


              

                                                                    







































































































































































































                                                                                                                                  
                                                         
 

                                                    
 

                              
 
                                                



                                                 
                                                                           

                            
















                                    
                                                       
                                                            



                 




                                                
                      
                                                    












                                                                  
                                    




                                


                                                          
                              
   
 

                                         
                                                 



                 
                                           









































































































































































































                                                                                                                                   
/*
 * FTP Server for ESP8266/ESP32
 * based on FTP Serveur for Arduino Due and Ethernet shield (W5100) or WIZ820io (W5200)
 * based on Jean-Michel Gallego's work
 * modified to work with esp8266 SPIFFS by David Paiva david@nailbuster.com
 * modified to work with esp8266 LitteFS by Daniel Plasa dplasa@gmail.com
 * Also done some code reworks and all string contants are now in flash memory 
 * by using F(), PSTR() ... on the string literals.  
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "espFtpServer.h"

#ifdef ESP8266
#include <ESP8266WiFi.h>
#elif defined ESP32
#include <WiFi.h>
#endif

#include "espFtpCommands.h"

WiFiServer controlServer(FTP_CTRL_PORT);
WiFiServer dataServer(FTP_DATA_PORT_PASV);

// helper macros
#define FTP_STR(s) FTP_STR2(s)
#define FTP_STR2(s) #s
#define FTP_SEND_MSG(code, fmt, ...)                                     \
  do                                                                     \
  {                                                                      \
    FTP_DEBUG_MSG(">>> " FTP_STR(code) " " fmt, ##__VA_ARGS__);          \
    control.printf_P(PSTR(FTP_STR(code) " " fmt "\r\n"), ##__VA_ARGS__); \
  } while (0)

#define FTP_SEND_DASHMSG(code, fmt, ...)                                 \
  do                                                                     \
  {                                                                      \
    FTP_DEBUG_MSG(">>> " FTP_STR(code) "-" fmt, ##__VA_ARGS__);          \
    control.printf_P(PSTR(FTP_STR(code) "-" fmt "\r\n"), ##__VA_ARGS__); \
  } while (0)

// some constants
static const char aSpace[] PROGMEM = " ";
static const char aSlash[] PROGMEM = "/";

// constructor
FtpServer::FtpServer(FS &_FSImplementation) : THEFS(_FSImplementation) {}

void FtpServer::begin(const String &uname, const String &pword)
{
  _FTP_USER = uname;
  _FTP_PASS = pword;

  iniVariables();

  // Tells the ftp server to begin listening for incoming connections
  controlServer.begin();
  dataServer.begin();
}

void FtpServer::stop()
{
  abortTransfer();
  disconnectClient(false);
  controlServer.stop();
  dataServer.stop();
}

void FtpServer::iniVariables()
{
  // Default Data connection is Active
  dataPassiveConn = true;

  // Set the root directory
  cwd = FPSTR(aSlash);

  // init internal status vars
  cmdState = cInit;
  transferState = tIdle;
  rnFrom.clear();

  // reset control connection input buffer, clear previous command
  cmdLine.clear();
  cmdString.clear();
  parameters.clear();
  command = 0;

  // free any used fileBuffer
  freeBuffer();
}

void FtpServer::handleFTP()
{
  //
  // control connection state sequence is
  //  cInit
  //    |
  //    V
  //  cWait
  //    |
  //    V
  //  cCheck -----------+
  //    |               | (no username but password set)
  //    V               |
  //  cUserId ----------+---+
  //    |               |   |
  //    +<--------------+   |
  //    V                   | (no password set)
  //  cPassword             |
  //    |                   |
  //    +<------------------+
  //    V
  //  cLoginOk
  //    |
  //    V
  //  cProcess
  //

  // if ((int32_t)(millisDelay - millis()) > 0)
  //   return;

  if (cmdState == cInit)
  {
    if (control.connected())
    {
      abortTransfer();
      disconnectClient(false);
    }
    iniVariables();
    cmdState = cWait;
  }

  else if (cmdState == cWait) // FTP control server waiting for connection
  {
    if (controlServer.hasClient())
    {
      control = controlServer.available();

      // wait 10s for login command
      updateTimeout(10);
      cmdState = cCheck;
    }
  }

  else if (cmdState == cCheck) // FTP control server check/setup control connection
  {
    if (control.connected()) // A client connected, say "220 Hello client!"
    {
      FTP_DEBUG_MSG("control server got connection from %s:%d",
                    control.remoteIP().toString().c_str(), control.remotePort());

      FTP_SEND_MSG(220, "(espFTP " FTP_SERVER_VERSION ")");

      if (_FTP_USER.length())
      {
        // FTP_SEND_MSG(332, "Need account for login.");
        cmdState = cUserId;
      }
      else if (_FTP_PASS.length())
      {
        // FTP_SEND_MSG(331, "Please specify the password.");
        cmdState = cPassword;
      }
      else
      {
        cmdState = cLoginOk;
      }
    }
  }

  else if (cmdState == cLoginOk) // tell client "Login ok!"
  {
    FTP_SEND_MSG(230, "Login successful.");
    updateTimeout(sTimeOut);
    cmdState = cProcess;
  }

  //
  // all other command states need to process commands froms control connection
  //
  else if (readChar() > 0)
  {
    // enforce USER than PASS commands before anything else
    if (((cmdState == cUserId) && (FTP_CMD(USER) != command)) ||
        ((cmdState == cPassword) && (FTP_CMD(PASS) != command)))
    {
      FTP_SEND_MSG(530, "Please login with USER and PASS.");
      FTP_DEBUG_MSG("ignoring before login: cwd=%s cmd[%x]=%s, params='%s'", cwd.c_str(), command, cmdString.c_str(), parameters.c_str());
      command = 0;
      return;
    }

    // process the command
    int8_t rc = processCommand();
    // returns
    // -1 : command processing indicates, we have to close control (e.g. QUIT)
    //  0 : not yet finished, just call processCommend() again
    //  1 : finished
    if (rc < 0)
    {
      cmdState = cInit;
    }
    if (rc > 0)
    {
      // clear current command, so readChar() can fetch the next command
      command = 0;

      // command was successful, update command state
      if (cmdState == cUserId)
      {
        if (_FTP_PASS.length())
        {
          // wait 10s for PASS command
          updateTimeout(10);
          FTP_SEND_MSG(331, "Please specify the password.");
          cmdState = cPassword;
        }
        else
        {
          cmdState = cLoginOk;
        }
      }
      else if (cmdState == cPassword)
      {
        cmdState = cLoginOk;
      }
      else
      {
        updateTimeout(sTimeOut);
      }
    }
  }

  //
  // general connection handling
  // (if we have an established control connection)
  //
  if (cmdState >= cCheck)
  {
    // detect lost/closed by remote connections
    if (!control.connected() || !control)
    {
      cmdState = cInit;
      FTP_DEBUG_MSG("client lost or disconnected");
    }

    // check for timeout
    if (!((int32_t)(millisEndConnection - millis()) > 0))
    {
      FTP_SEND_MSG(530, "Timeout.");
      FTP_DEBUG_MSG("client connection timed out");
      cmdState = cInit;
    }

    // handle data file transfer
    if (transferState == tRetrieve) // Retrieve data
    {
      if (!doRetrieve())
      {
        closeTransfer();
        transferState = tIdle;
      }
    }
    else if (transferState == tStore) // Store data
    {
      if (!doStore())
      {
        closeTransfer();
        transferState = tIdle;
      }
    }
  }
}

void FtpServer::disconnectClient(bool gracious)
{
  FTP_DEBUG_MSG("Disconnecting client");
  abortTransfer();
  if (gracious)
  {
    FTP_SEND_MSG(221, "Goodbye.");
  }
  else
  {
    FTP_SEND_MSG(231, "Service terminated.");
  }
  control.stop();
}

int8_t FtpServer::processCommand()
{
  // assume successful operation by default
  int8_t rc = 1;

  // make the full path of parameters (even if this makes no sense for all commands)
  String path = getFileName(parameters, true);
  FTP_DEBUG_MSG("processing: cmd=%s[%x], params='%s' (cwd='%s')", cmdString.c_str(), command, parameters.c_str());

  ///////////////////////////////////////
  //                                   //
  //      ACCESS CONTROL COMMANDS      //
  //                                   //
  ///////////////////////////////////////

  //
  //  USER - Provide username
  //
  if (FTP_CMD(USER) == command)
  {
    if (_FTP_USER.length() && (_FTP_USER != parameters))
    {
      FTP_SEND_MSG(430, "User not found.");
      command = 0;
      rc = 0;
    }
    else
    {
      FTP_DEBUG_MSG("USER ok");
    }
  }

  //
  //  PASS - Provide password
  //
  else if (FTP_CMD(PASS) == command)
  {
    if (_FTP_PASS.length() && (_FTP_PASS != parameters))
    {
      FTP_SEND_MSG(430, "Password invalid.");
      command = 0;
      rc = 0;
    }
    else
    {
      FTP_DEBUG_MSG("PASS ok");
    }
  }

  //
  //  QUIT
  //
  else if (FTP_CMD(QUIT) == command)
  {
    disconnectClient();
    rc = -1;
  }

  //
  //  NOOP
  //
  else if (FTP_CMD(NOOP) == command)
  {
    FTP_SEND_MSG(200, "Zzz...");
  }

  //
  //  CDUP - Change to Parent Directory
  //
  else if (FTP_CMD(CDUP) == command)
  {
    // up one level
    cwd = getPathName("", false);
    FTP_SEND_MSG(250, "Directory successfully changed.");
  }

  //
  //  CWD - Change Working Directory
  //
  else if (FTP_CMD(CWD) == command)
  {
    if (parameters == F(".")) // 'CWD .' is the same as PWD command
    {
      command = FTP_CMD(PWD); // make CWD a PWD command ;-)
      rc = 0;                 // indicate we need another processCommand() call
    }
    else if (parameters == F("..")) // 'CWD ..' is the same as CDUP command
    {
      command = FTP_CMD(CDUP); // make CWD a CDUP command ;-)
      rc = 0;                  // indicate we need another processCommand() call
    }
    else
    {
#if (defined esp8266FTPServer_SPIFFS)
      // SPIFFS has no directories, it's always ok
      cwd = path;
      FTP_SEND_MSG(250, "Directory successfully changed.");
#else
      // check if directory exists
      file = THEFS.open(path, "r");
      if (file.isDirectory())
      {
        cwd = path;
        FTP_SEND_MSG(250, "Directory successfully changed.");
      }
      else
      {
        FTP_SEND_MSG(550, "Failed to change directory.");
      }
      file.close();
#endif
    }
  }

  //
  //  PWD - Print Directory
  //
  else if (FTP_CMD(PWD) == command)
  {
    FTP_SEND_MSG(257, "\"%s\" is the current directory.", cwd.c_str());
  }

  ///////////////////////////////////////
  //                                   //
  //    TRANSFER PARAMETER COMMANDS    //
  //                                   //
  ///////////////////////////////////////

  //
  //  MODE - Transfer Mode
  //
  else if (FTP_CMD(MODE) == command)
  {
    if (parameters == F("S"))
      FTP_SEND_MSG(504, "Only S(tream) mode is suported");
    else
      FTP_SEND_MSG(200, "Mode set to S.");
  }

  //
  //  PASV - Passive data connection management
  //
  else if (FTP_CMD(PASV) == command)
  {
    // stop a possible previous data connection
    data.stop();
    // tell client to open data connection to our ip:dataPort
    dataPort = FTP_DATA_PORT_PASV;
    dataPassiveConn = true;
    String ip = control.localIP().toString();
    ip.replace(".", ",");
    FTP_SEND_MSG(227, "Entering Passive Mode (%s,%d,%d).", ip.c_str(), dataPort >> 8, dataPort & 255);
  }

  //
  //  PORT - Data Port, Active data connection management
  //
  else if (FTP_CMD(PORT) == command)
  {
    if (data)
      data.stop();

    // parse IP and data port of "PORT ip,ip,ip,ip,port,port"
    uint8_t parsecount = 0;
    uint8_t tmp[6];
    const char *p = parameters.c_str();
    while (parsecount < sizeof(tmp))
    {
      tmp[parsecount++] = atoi(p);
      p = strchr(p, ',');
      if (NULL == p || *(++p) == '\0')
        break;
    }
    if (parsecount < sizeof(tmp))
    {
      FTP_SEND_MSG(501, "Can't interpret parameters");
    }
    else
    {
      // copy first 4 bytes = IP
      for (uint8_t i = 0; i < 4; ++i)
        dataIP[i] = tmp[i];
      // data port is 5,6
      dataPort = tmp[4] * 256 + tmp[5];
      FTP_SEND_MSG(200, "PORT command successful");
      dataPassiveConn = false;
      FTP_DEBUG_MSG("Data connection management Active, using %s:%u", dataIP.toString().c_str(), dataPort);
    }
  }

  //
  //  STRU - File Structure
  //
  else if (FTP_CMD(STRU) == command)
  {
    if (parameters == F("F"))
      FTP_SEND_MSG(504, "Only F(ile) is suported");
    else
      FTP_SEND_MSG(200, "Structure set to F.");
  }

  //
  //  TYPE - Data Type
  //
  else if (FTP_CMD(TYPE) == command)
  {
    if (parameters == F("A"))
      FTP_SEND_MSG(200, "TYPE is now ASII.");
    else if (parameters == F("I"))
      FTP_SEND_MSG(200, "TYPE is now 8-bit Binary.");
    else
      FTP_SEND_MSG(504, "Unrecognised TYPE.");
  }

  ///////////////////////////////////////
  //                                   //
  //        FTP SERVICE COMMANDS       //
  //                                   //
  ///////////////////////////////////////

  //
  //  ABOR - Abort
  //
  else if (FTP_CMD(ABOR) == command)
  {
    abortTransfer();
    FTP_SEND_MSG(226, "Data connection closed");
  }

  //
  //  DELE - Delete a File
  //
  else if (FTP_CMD(DELE) == command)
  {
    if (parameters.length() == 0)
      FTP_SEND_MSG(501, "No file name");
    else
    {
      if (!THEFS.exists(path))
      {
        FTP_SEND_MSG(550, "Delete operation failed, file '%s' not found.", path.c_str());
      }
      else if (THEFS.remove(path))
      {
        FTP_SEND_MSG(250, "Delete operation successful.");
      }
      else
      {
        FTP_SEND_MSG(450, "Delete operation failed.");
      }
    }
  }

  //
  //  LIST - List directory contents
  //  MLSD - Listing for Machine Processing (see RFC 3659)
  //  NLST - Name List
  //
  else if ((FTP_CMD(LIST) == command) || (FTP_CMD(MLSD) == command) || (FTP_CMD(NLST) == command))
  {
    rc = dataConnect(); // returns -1: no data connection, 0: need more time, 1: data ok
    if (rc < 0)
    {
      FTP_SEND_MSG(425, "No data connection");
      rc = 1; // mark command as processed
    }
    else if (rc > 0)
    {
      FTP_SEND_MSG(150, "Accepted data connection");
      uint16_t dirCount = 0;
      Dir dir = THEFS.openDir(path);
      while (dir.next())
      {
        ++dirCount;
        bool isDir = false;
        String fn = dir.fileName();
        if (cwd == FPSTR(aSlash) && fn[0] == '/')
          fn.remove(0, 1);
        isDir = dir.isDirectory();
        if (FTP_CMD(LIST) == command)
        {
          if (isDir)
          {
            data.printf_P(PSTR("+d\r\n,\t%s\r\n"), fn.c_str());
          }
          else
          {
            data.printf_P(PSTR("+r,s%lu\r\n,\t%s\r\n"), (uint32_t)dir.fileSize(), fn.c_str());
          }
        }
        else if (FTP_CMD(MLSD) == command)
        {
          // "modify=20170122163911;type=dir;UNIX.group=0;UNIX.mode=0775;UNIX.owner=0; dirname"
          // "modify=20170121000817;size=12;type=file;UNIX.group=0;UNIX.mode=0644;UNIX.owner=0; filename"
          file = dir.openFile("r");
          data.printf_P(PSTR("modify=%s;UNIX.group=0;UNIX.owner=0;UNIX.mode="), makeDateTimeStr(file.getLastWrite()).c_str());
          file.close();
          if (isDir)
          {
            data.printf_P(PSTR("0755;type=dir; "));
          }
          else
          {
            data.printf_P(PSTR("0644;size=%lu;type=file; "), (uint32_t)dir.fileSize());
          }
          data.printf_P(PSTR("%s\r\n"), fn.c_str());
        }
        else if (FTP_CMD(NLST) == command)
        {
          data.println(fn);
        }
        else
        {
          FTP_DEBUG_MSG("Implemetation of %s [%x] command - internal BUG", cmdString.c_str(), command);
        }
      }

      if (FTP_CMD(MLSD) == command)
      {
        control.println(F("226-options: -a -l\r\n"));
      }
      FTP_SEND_MSG(226, "%d matches total", dirCount);
    }
#if defined ESP32
    File root = THEFS.open(cwd);
    if (!root)
    {
      FTP_SEND_MSG(550, "Can't open directory " + cwd);
      // return;
    }
    else
    {
      // if(!root.isDirectory()){
      // 		FTP_DEBUG_MSG("Not a directory: '%s'", cwd.c_str());
      // 		return;
      // }

      File file = root.openNextFile();
      while (file)
      {
        if (file.isDirectory())
        {
          data.println("+r,s <DIR> " + String(file.name()));
          // Serial.print("  DIR : ");
          // Serial.println(file.name());
          // if(levels){
          // 	listDir(fs, file.name(), levels -1);
          // }
        }
        else
        {
          String fn, fs;
          fn = file.name();
          // fn.remove(0, 1);
          fs = String(file.size());
          data.println("+r,s" + fs);
          data.println(",\t" + fn);
          nm++;
        }
        file = root.openNextFile();
      }
      FTP_SEND_MSG(226, "%s matches total", nm);
    }
#endif
    data.stop();
  }

#if defined ESP32
  //
  //  FIXME MLSD ESP32
  //
  else if (!strcmp(command, "MLSD"))
  {
    File root = THEFS.open(cwd);
    // if(!root){
    // 		control.println( "550, "Can't open directory " + cwd );
    // 		// return;
    // } else {
    // if(!root.isDirectory()){
    // 		Serial.println("Not a directory");
    // 		return;
    // }

    File file = root.openNextFile();
    while (file)
    {
      // if(file.isDirectory()){
      // 	data.println( "+r,s <DIR> " + String(file.name()));
      // 	// Serial.print("  DIR : ");
      // 	// Serial.println(file.name());
      // 	// if(levels){
      // 	// 	listDir(fs, file.name(), levels -1);
      // 	// }
      // } else {
      String fn, fs;
      fn = file.name();
      fn.remove(0, 1);
      fs = String(file.size());
      data.println("Type=file;Size=" + fs + ";" + "modify=20000101160656;" + " " + fn);
      nm++;
      // }
      file = root.openNextFile();
    }
    FTP_SEND_MSG(226, "-options: -a -l");
    FTP_SEND_MSG(226, "%d matches total", nm);
    // }
    data.stop();
  }
  //
  // NLST
  //
  else if (!strcmp(command, "NLST"))
  {
    File root = THEFS.open(cwd);
    if (!root)
    {
      FTP_SEND_MSG(550, "Can't open directory %s\n"), cwd.c_str());
    }
    else
    {
      File file = root.openNextFile();
      while (file)
      {
        data.println(file.name());
        nm++;
        file = root.openNextFile();
      }
      FTP_SEND_MSG(226, "%d matches total", nm);
    }
    data.stop();
  }
#endif

  //
  //  RETR - Retrieve
  //
  else if (FTP_CMD(RETR) == command)
  {
    if (parameters.length() == 0)
    {
      FTP_SEND_MSG(501, "No file name");
    }
    else
    {
      // open the file if not opened before (when re-running processCommand() since data connetion needs time)
      if (!file)
        file = THEFS.open(path, "r");
      if (!file)
      {
        FTP_SEND_MSG(550, "File '%s' not found.", parameters.c_str());
      }
      else if (!file.isFile())
      {
        FTP_SEND_MSG(450, "Cannot open file \"%s\".", parameters.c_str());
      }
      else
      {
        rc = dataConnect(); // returns -1: no data connection, 0: need more time, 1: data ok
        if (rc < 0)
        {
          FTP_SEND_MSG(425, "No data connection");
          rc = 1; // mark command as processed
        }
        else if (rc > 0)
        {
          transferState = tRetrieve;
          millisBeginTrans = millis();
          bytesTransfered = 0;
          uint32_t fs = file.size();
          if (allocateBuffer(fs > 32768 ? 32768 : fs))
          {
            FTP_DEBUG_MSG("Sending file '%s'", path.c_str());
            FTP_SEND_MSG(150, "%lu bytes to download", fs);
          }
          else
          {
            closeTransfer();
            FTP_SEND_MSG(451, "Internal error. Not enough memory.");
          }
        }
      }
    }
  }

  //
  //  STOR - Store
  //
  else if (FTP_CMD(STOR) == command)
  {
    if (parameters.length() == 0)
    {
      FTP_SEND_MSG(501, "No file name.");
    }
    else
    {
      FTP_DEBUG_MSG("STOR '%s'", path.c_str());
      if (!file)
        file = THEFS.open(path, "w");
      if (!file)
      {
        FTP_SEND_MSG(451, "Cannot open/create \"%s\"", path.c_str());
      }
      else
      {
        rc = dataConnect(); // returns -1: no data connection, 0: need more time, 1: data ok
        if (rc < 0)
        {
          FTP_SEND_MSG(425, "No data connection");
          file.close();
          rc = 1; // mark command as processed
        }
        else if (rc > 0)
        {
          transferState = tStore;
          millisBeginTrans = millis();
          bytesTransfered = 0;
          if (allocateBuffer(2048))
          {
            FTP_DEBUG_MSG("Receiving file '%s' => %s", parameters.c_str(), path.c_str());
            FTP_SEND_MSG(150, "Connected to port %d", dataPort);
          }
          else
          {
            closeTransfer();
            FTP_SEND_MSG(451, "Internal error. Not enough memory.");
          }
        }
      }
    }
  }

  //
  //  MKD - Make Directory
  //
  else if (FTP_CMD(MKD) == command)
  {
#if (defined esp8266FTPServer_SPIFFS)
    FTP_SEND_MSG(550, "Create directory operation failed."); //not support on SPIFFS
#else
    FTP_DEBUG_MSG("mkdir(%s)", path.c_str());
    if (THEFS.mkdir(path))
    {
      FTP_SEND_MSG(257, "\"%s\" created.", path.c_str());
    }
    else
    {
      FTP_SEND_MSG(550, "Create directory operation failed.");
    }
#endif
  }

  //
  //  RMD - Remove a Directory
  //
  else if (FTP_CMD(RMD) == command)
  {
#if (defined esp8266FTPServer_SPIFFS)
    FTP_SEND_MSG(550, "Remove directory operation failed."); //not support on SPIFFS
#else
    // check directory for files
    Dir dir = THEFS.openDir(path);
    if (dir.next())
    {
      //only delete if dir is empty!
      FTP_SEND_MSG(550, "Remove directory operation failed, directory is not empty.");
    }
    else
    {
      THEFS.rmdir(path);
      FTP_SEND_MSG(250, "Remove directory operation successful.");
    }
#endif
  }
  //
  //  RNFR - Rename From
  //
  else if (FTP_CMD(RNFR) == command)
  {
    if (parameters.length() == 0)
      FTP_SEND_MSG(501, "No file name");
    else
    {
      if (!THEFS.exists(path))
        FTP_SEND_MSG(550, "File \"%s\" not found.", path.c_str());
      else
      {
        FTP_SEND_MSG(350, "RNFR accepted - file \"%s\" exists, ready for destination", path.c_str());
        rnFrom = path;
      }
    }
  }
  //
  //  RNTO - Rename To
  //
  else if (FTP_CMD(RNTO) == command)
  {
    if (rnFrom.length() == 0)
      FTP_SEND_MSG(503, "Need RNFR before RNTO");
    else if (parameters.length() == 0)
      FTP_SEND_MSG(501, "No file name");
    else if (THEFS.exists(path))
      FTP_SEND_MSG(553, "\"%s\" already exists.", parameters.c_str());
    else
    {
      FTP_DEBUG_MSG("Renaming '%s' to '%s'", rnFrom.c_str(), path.c_str());
      if (THEFS.rename(rnFrom, path))
        FTP_SEND_MSG(250, "File successfully renamed or moved");
      else
        FTP_SEND_MSG(451, "Rename/move failure.");
    }
    rnFrom.clear();
  }

  ///////////////////////////////////////
  //                                   //
  //   EXTENSIONS COMMANDS (RFC 3659)  //
  //                                   //
  ///////////////////////////////////////

  //
  //  FEAT - New Features
  //
  else if (FTP_CMD(FEAT) == command)
  {
    FTP_SEND_DASHMSG(211, "Features:\r\n  MLSD\r\n  MDTM\r\n  SIZE\r\n211 End.");
  }

  //
  //  MDTM - File Modification Time (see RFC 3659)
  //
  else if (FTP_CMD(MDTM) == command)
  {
    file = THEFS.open(path, "r");
    if ((!file) || (0 == parameters.length()))
    {
      FTP_SEND_MSG(550, "Unable to retrieve time");
    }
    else
    {
      FTP_SEND_MSG(213, "%s", makeDateTimeStr(file.getLastWrite()).c_str());
    }
    file.close();
  }

  //
  //  SIZE - Size of the file
  //
  else if (FTP_CMD(SIZE) == command)
  {
    file = THEFS.open(path, "r");
    if ((!file) || (0 == parameters.length()))
    {
      FTP_SEND_MSG(450, "Cannot open file.");
    }
    else
    {
      FTP_SEND_MSG(213, "%lu", (uint32_t)file.size());
    }
    file.close();
  }

  //
  //  SITE - System command
  //
  else if (FTP_CMD(SITE) == command)
  {
    FTP_SEND_MSG(502, "SITE command not implemented");
  }

  //
  //  SYST - System information
  //
  else if (FTP_CMD(SYST) == command)
  {
    FTP_SEND_MSG(215, "UNIX Type: L8");
  }

  //
  //  Unrecognized commands ...
  //
  else
  {
    FTP_DEBUG_MSG("Unknown command: %s [%#x], param: '%s')", cmdString.c_str(), command, parameters.c_str());
    FTP_SEND_MSG(500, "unknown command \"%s\"", cmdString.c_str());
  }

  return rc;
}

int8_t FtpServer::dataConnect()
{
  int8_t rc = 1; // assume success

  if (!dataPassiveConn)
  {
    // active mode
    // open our own data connection
    data.stop();
    FTP_DEBUG_MSG("Open active data connection to %s:%u", dataIP.toString().c_str(), dataPort);
    data.connect(dataIP, dataPort);
    if (!data.connected())
      rc = -1;
  }
  else
  {
    // passive mode
    // wait for data connection from the client
    if (!data.connected())
    {
      if (dataServer.hasClient())
      {
        data.stop();
        data = dataServer.available();
        FTP_DEBUG_MSG("Got incoming (passive) data connection from %s:%u", data.remoteIP().toString().c_str(), data.remotePort());
      }
      else
      {
        // give me more time waiting for a data connection
        rc = 0;
      }
    }
  }
  return rc;
}

uint16_t FtpServer::allocateBuffer(uint16_t desiredBytes)
{
  // allocate a big buffer for file transfers
  uint16_t maxBlock = ESP.getMaxFreeBlockSize() / 2;

  if (desiredBytes > maxBlock)
    desiredBytes = maxBlock;

  while (fileBuffer == NULL && desiredBytes > 0)
  {
    fileBuffer = (uint8_t *)malloc(desiredBytes);
    if (NULL == fileBuffer)
    {
      FTP_DEBUG_MSG("Cannot allocate buffer for file transfer, re-trying");
      // try with less bytes
      desiredBytes--;
    }
    else
    {
      fileBufferSize = desiredBytes;
    }
  }
  return fileBufferSize;
}

void FtpServer::freeBuffer()
{
  free(fileBuffer);
  fileBuffer = NULL;
}

bool FtpServer::doRetrieve()
{
  // data connection lost or no more bytes to transfer?
  if (!data.connected() || (bytesTransfered >= file.size()))
  {
    return false;
  }

  // how many bytes to transfer left?
  uint32_t nb = (file.size() - bytesTransfered);
  if (nb > fileBufferSize)
    nb = fileBufferSize;

  // transfer the file
  FTP_DEBUG_MSG("Transfer %d bytes fs->client", nb);
  nb = file.readBytes((char *)fileBuffer, nb);
  if (nb > 0)
  {
    data.write(fileBuffer, nb);
    bytesTransfered += nb;
  }

  return (nb > 0);
}

bool FtpServer::doStore()
{
  // Avoid blocking by never reading more bytes than are available
  int16_t navail = data.available();

  if (navail > 0)
  {
    if (navail > fileBufferSize)
      navail = fileBufferSize;
    FTP_DEBUG_MSG("Transfer %d bytes client->fs", navail);
    navail = data.read(fileBuffer, navail);
    file.write(fileBuffer, navail);
    bytesTransfered += navail;
  }

  if (!data.connected() && (navail <= 0))
  {
    // connection closed or no more bytes to read
    return false;
  }
  else
  {
    // inidcate, we need to be called again
    return true;
  }
}

void FtpServer::closeTransfer()
{
  uint32_t deltaT = (int32_t)(millis() - millisBeginTrans);
  if (deltaT > 0 && bytesTransfered > 0)
  {
    FTP_SEND_MSG(226, "File successfully transferred, %lu ms, %f kB/s.", deltaT, float(bytesTransfered) / deltaT);
  }
  else
    FTP_SEND_MSG(226, "File successfully transferred");

  freeBuffer();
  file.close();
  data.stop();
}

void FtpServer::abortTransfer()
{
  if (transferState > tIdle)
  {
    file.close();
    data.stop();
    FTP_SEND_MSG(426, "Transfer aborted");
  }
  freeBuffer();
  transferState = tIdle;
}

// Read a char from client connected to ftp server
//
//  returns:
//    -1 if cmdLine too long
//     0 cmdLine still incomplete (no \r or \n received yet)
//     1 cmdLine processed, command and parameters available

int8_t FtpServer::readChar()
{
  // only read/parse, if the previous command has been fully processed!
  if (command)
    return 1;

  while (control.available())
  {
    char c = control.read();
    // FTP_DEBUG_MSG("readChar() cmdLine='%s' <= %c", cmdLine.c_str(), c);

    // substitute '\' with '/'
    if (c == '\\')
      c = '/';

    // nl detected? then process line
    if (c == '\n' || c == '\r')
    {
      cmdLine.trim();

      // but only if we got at least chars in the line!
      if (0 == cmdLine.length())
        break;

      // search for space between command and parameters
      int pos = cmdLine.indexOf(FPSTR(aSpace));
      if (pos > 0)
      {
        parameters = cmdLine.substring(pos + 1);
        parameters.trim();
        cmdLine.remove(pos);
      }
      else
      {
        parameters.remove(0);
      }
      cmdString = cmdLine;

      // convert command to upper case
      cmdString.toUpperCase();

      // convert the (up to 4 command chars to numerical value)
      command = *(const uint32_t *)cmdString.c_str();

      // clear cmdline
      cmdLine.clear();
      FTP_DEBUG_MSG("readChar() success, command=%x, cmdString='%s', params='%s'", command, cmdString.c_str(), parameters.c_str());
      return 1;
    }
    else
    {
      // just add char
      cmdLine += c;
      if (cmdLine.length() > FTP_CMD_SIZE)
      {
        cmdLine.clear();
        FTP_SEND_MSG(500, "Line too long");
      }
    }
  }
  return 0;
}

// Get the complete path from cwd + parameters or complete filename from cwd + parameters
//
// 3 possible cases: parameters can be absolute path, relative path or only the name
//
// returns:
//    path WITHOUT file-/dirname (fullname=false)
//    full path WITH file-/dirname (fullname=true)
String FtpServer::getPathName(const String &param, bool fullname)
{
  String tmp;

  // is param an absoulte path?
  if (param[0] == '/')
  {
    tmp = param;
  }
  else
  {
    // start with cwd
    tmp = cwd;

    // if param != "" then add param
    if (param.length())
    {
      if (!tmp.endsWith(FPSTR(aSlash)))
        tmp += '/';
      tmp += param;
    }
    // => tmp becomes cdw [ + '/' + param ]
  }

  // strip filename
  if (!fullname)
  {
    // search rightmost '/'
    int lastslash = tmp.lastIndexOf(FPSTR(aSlash));
    if (lastslash >= 0)
    {
      tmp.remove(lastslash);
    }
  }
  // sanetize:
  // "" -> "/"
  // "/some/path/" => "/some/path"
  while (tmp.length() > 1 && tmp.endsWith(FPSTR(aSlash)))
    tmp.remove(cwd.length() - 1);
  if (tmp.length() == 0)
    tmp += '/';
  return tmp;
}

// Get the [complete] file name from cwd + parameters
//
// 3 possible cases: parameters can be absolute path, relative path or only the filename
//
// returns:
//    filename or filename with complete path
String FtpServer::getFileName(const String &param, bool fullFilePath)
{
  // build the filename with full path
  String tmp = getPathName(param, true);

  if (!fullFilePath)
  {
    // strip path
    // search rightmost '/'
    int lastslash = tmp.lastIndexOf(FPSTR(aSlash));
    if (lastslash > 0)
    {
      tmp.remove(0, lastslash);
    }
  }

  return tmp;
}

// Formats YYYYMMDDHHMMSS from a time_t timestamp
//
// uses the buf of the FtpServer to store the date string
//
// parameters:
//    timestamp
//
// return:
//    pointer to buf[0]

String FtpServer::makeDateTimeStr(time_t ft)
{
  struct tm *_tm = gmtime(&ft);
  String tmp;
  tmp.reserve(17);
  strftime((char *)tmp.c_str(), 17, "%Y%m%d%H%M%S", _tm);
  return tmp;
}

void FtpServer::updateTimeout(uint16_t s)
{
  millisEndConnection = s;
  millisEndConnection *= 60000UL;
  millisEndConnection += millis();
}